The present invention relates to an improvement of a sheet feeding apparatus in an image recording apparatus. More particularly, the present invention relates to an improvement, of a driving means for an elevation type sheet feed base plate.
In an image recording apparatus such as a copying apparatus, recording sheets of various types are respectively loaded in exclusive sheet feed cassettes, the cassettes are loaded into the image recording apparatus and recording sheets of a desired size can be fed one by one.
However, the amount of recording sheets which can be loaded in the above cassettes, is not so large, about 200 sheets at the most. Therefore, every time the sheets are used up, the cassette must be detached from the image recording apparatus so that the recording sheets can be loaded into the cassette, and loaded again into the image recording apparatus. Accordingly, when the foregoing detaching from and loading into the apparatus is frequently carried out, it is troublesome and the recording efficiency is lowered.
In order to avoid such problems, a sheet feeding apparatus provided with an elevation type sheet feed base plate is widely used in which a larger amount of recording sheets, which are frequently used as a main size, can be stored.
As the sheet feeding apparatus described above, the apparatus which has been disclosed in Japanese Utility Model Open to Public Inspection No. 180637/1988, is widely known.
In the sheet feeding apparatus provided with the elevation type sheet feed base plate in which a large amount of recording sheets can be stored, an apparatus having a storage capacity of more than 500 sheets has now been realized. However, a sheet feeding apparatus having a storage capacity in which 1000, or 1500 recording sheets can be stored, is required to be realized.
However, in order to load such a large amount of sheets onto the sheet feed base plate and to elevate it freely, large driving power is necessary. That is, large output power of a driving motor is necessary, which is beyond that used in an ordinary office. Further, the loading operation of the recording sheets onto the elevation base plate is inevitably troublesome.